1) the 5 classes are handled a little like in Bad Company 2. You pick your class, and then the XP you earn can be spent within that class through a mix of standard “unlock when you hit level 10” and picking and choosing abilities.
If you play enough, you’ll be able to unlock everything there is on offer. So if you bought something you didn’t like, just play some more and you can buy the other things.
It won’t restrict you to playing just a single class. You can still play them all.

2) Agreed, it’s a little foggy, but there might be a toggle to switch between party/clan chat and whole team chat. It is, however, implied that the game somehow does this magically.

3)Body Count is well and good, but here it’s a more streamlined experience. Spawning around the map close-ish to the action, rather than forever spawning within your base… A little CoD-ified, but they did say you can capture spawn points for your team, so a little more involved than just running around.

4)No word on this yet, but I doubt it. Would be a bit confusing.

5)Doesn’t seem like it. They only said 2 “new” game modes, one of which is TDM, the other of which is the Operations mode (seems to be the replacement/evolution of KZ2’s MP)

6) No weapon customisation. But there’s more weapons per class, (overlapping from one to another), and from the vids, it could be that there’s class specific tweaks (such as RDS or 4x scopes) to certain guns.

7) The new scoring system gives us more points, so we’ll be seeing kill assist points. There could be points bonuses for getting kill streaks, but there’s no word (and I really hope there aren’t) on any in-game advantages like missile attacks… Just doesn’t feel like it’d fit in.